A vehicle has a rear-view mirror therein to provide a rear-seat view and a rear view for a driver and, which is tiltably mounted on a ceiling located above a driver's seat and a passenger's seat.
A rear-view mirror assembly comprises a housing assembled onto the ceiling surface by a ball joint and mirror glass mounted on a front surface of the housing.
The mirror glass in the vehicle typically has a flat reflection surface with a predetermined thickness. A headlight, particularly a full beam, of a vehicle behind the driver is reflected to the mirror glass, thereby causing a glare to a driver.
To prevent the reflection from the mirror glass, a frameless rear-view mirror assembly has been introduced, which controls light reflectance.
A frameless rear-view mirror assembly in the related art will be described below with reference to FIGS. 1 to 3. Referring to FIGS. 1 and 2, a frameless prism glass 20 is mounted to a front opening of a housing 10. The prism glass 20 has a thickness which gradually decreases from top to bottom.
In this case, the housing 10 is tiltably mounted by a ball joint 12, and a lever 14 for controlling an angle of the housing 10 is connected to the ball joint 12. A front surface of the prism glass 20 includes a first reflection surface 21 that implements a night reflection mode. A rear surface of the prism glass 20 includes a second reflection surface 22 which is coated with a reflection material that implements a day reflection mode.
As illustrated in FIG. 2, in the day reflection mode, a rear object and light are reflected through the second reflection surface 22 of the prism glass 20, and thus, a driver can view the rear object reflected from the second reflection surface 22, and simultaneously, the light reflected on the second reflection surface 22 is introduced into eyes of the driver.
When the lever 14 is rotated downward around the ball joint 12 to tilt the housing 10 upward (approximately 3.5°) in order to decrease the light reflection in the night reflection mode, the prism glass 20 also tilts at the same angle together with the housing 10, and thus, the rear object and light are reflected through the first reflection surface 21.
As described above, in the night reflection mode, a reflection angle is controlled by tilting the prism glass 20, and as a result, the light introduced from the rear object (in particular, headlight of the rear vehicle) is reflected through the first reflection surface 21 while reflectance decreases. Consequently, a glare to the driver can be prevented.
However, according to the rear-view mirror assembly of the related art, when the rear object is reflected through the first and second reflection surfaces of the prism glass in the day reflection mode and the night reflection mode, a virtual image and a real image overlap with each other due to the characteristic of the prism glass, and therefore, a driver may recognize the rear object, but may feel uncomfortable.
In order to solve the above problem, various studies to reduce image overlapping have been introduced, for example, a vehicle rear-view mirror assembly as shown in FIG. 3 comprises a fixed reflector fixed to a rear-view mirror housing. A tilting reflector is arranged on a rear surface of the fixed reflector in a day reflection mode, and simultaneously, tilting in a night reflection mode. Here, a virtual image and a real image overlap with each other in the day reflection mode. A tilting trajectory of the tilting reflector for switching between the day reflection mode and the night reflection mode, is maintained to intuitively recognize a state of a reflection mode.
However, as illustrated in FIG. 3, a gap between a lever for tilting the tilting reflector and a slot formed on the bottom of the housing is formed, dust and foreign substances may penetrate into the inside of the housing from outside through the gap (the arrow in FIG. 3 indicates a penetration direction), and consequently, the penetrated dust and the like adhere onto the tilting reflector, thus deteriorating reflection performance of the tilting reflector.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the disclosure, and therefore, it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.